PacifiCare Health Systems Inc. said Tuesday that...

PacifiCare Health Systems Inc. said Tuesday that it may repurchase up to 500,000 shares of its common stock on the open market. The Cypress-based company, which owns and operates health maintenance organizations, has 11.5 million shares outstanding. Terry Hartshorn, president and chief executive, said the recent decline in overall stock prices may present “attractive opportunities . . . to acquire shares.” The company’s stock closed Tuesday at $14 per share, down from a 1990 high of $27.50.